Means for coating filaments



March 13, 1951 RYAN MEANS FOR COATING FILAMENTS Oi'iginal Filed Oct. 20, 1944 34/95 F/MMENT INVETO2 Hiker d (m 4p (OIJTED l .//C,.,C,/*

ATT RNEY Patented Mar. 13, 1951 UNITED STATES Ber were MEANS FOR coA frINc FILAMEN'IYS Albert Olen Ryan, Independence, Ky; assignor to Bedding Manufacturing Company, Inc., Norwalk, Oonn., a corporation of Delaware Original application October 20,1944, Serial No.

559,497. Divided and this application February 12, 1947, Serial No. 728,149 j 2 Claims.

This invention relates to improvements in means for coating filaments, and is more particularly directed to means for covering wires and the like with insulation, and this application; is a.

division of my co-pending application-Serial Number 559,497, filed October 20, 1944, onwhichj U. S. Patent No. 2,456,650 was issued December An object of this invention is to provide simple and improved means for forming a continuous. coating, such as insulation, about a filament,.s11ch as a wire.,

may function as a hardening material, moving with streamlined now in a restricted passage, so that as the filament, coating material, and confining material move along, the coating material gradually becomes hardened and coatstheenclosed filament. 3

Other objects and advantages of the present invention will appear from the following description of examples thereof, illustrated in', the ea. companying drawings, inwhich'zfl Fig. 1 is a vertical cross-sectional viewfoffa portion of my apparatus, with other apparatus indicated diagrammatically, of a preferred form of arrangement in accordance with the present invention;

Fig. 2 is an enlarged vertical cross-sectional view of a portion of the apparatus illustrated in Fig. 1.

The apparatus shown by way of example in the drawings may consist of a hollow cylindrical tube I having a relatively long section of uniform, small internal diameter throughout its length to its exit end, and a short section on one end of relatively greater internal diameter. In the form of invention shown, this tube is preferably mounted vertically, with the larger section on top. Within the larger section of the tube In is "While the filament to be coated, may bel8 for the coating material is fed into the top of the tube 'lll, as from a source it, and flows downw'ardly through the tube. The coating material 22 is fed into the inner'tube l2 and passes down-f wardly, outwardly through the nozzle I4 about the filament It. A source of coating material 24 will be connected to the tube I2.

Ihe, carrier liquid l8, after passing through the lower end 'of the tube Ill, ma be collected in a sump 26 for re-use; Apump 28 may be used to return this j naterial tothe source and, if they action to be described inmore detail later involves the use of ,a. heated carrier liquid, a heater generally kept under suitable tension over the rollers, if this, filamentis a wire it is necessary I that it be maintained free of bends or kinks, andit.,must be suitably centered. Within the tube l2 there may, therefore, be provided centering spiders. 32- to effect this result.

Ifit is desired to, coat the filament IS with latex; liquid latex will be used as a coating mate-- rial while heated glycerine may be used as the ..that the discharge speed of the latex from the mozzle-l4-. is identical with the speed of flow of the glycerine in contact with the latex at this discharge point, and the speed of both of the materials at their interface is preferably identical with mounted a. second hollow tube l2 having disthe speed of movement of the filament to be covered when the flow results from the hydraulic pressure above. The speeds are all so related to the viscosities of the materials used and the size of the filament, outer diameter ol the latex and the inside diameter of the very small tube it to bring about a condition known as streamlined or viscous flow. Under all conditions the glycerine surrounding the latex will drag along the inner surface of the tube whileat the interface of the glycerine and the latex the speed of each will be identical. When the speed of the filament is greater than the maximum speed in the latex due to hydraulic pressure, it produces a drag on the latex which will increase the rate of fiow. The lineal speed of the filament must be limited by conditions to insure that streamlined flow results. Under all the above conditions the glycerine will confine the latex to a definite size and shape by acting as a lubricating, mobile, confining wall and on moving downward through the tube [0, the latex will gradually become coagu- 30 may be, interposed .between the pump .28 and lated about the filament, forming the coating 22' indicated in Fig. 2. The coated filament is then drawn off over the rollers 34 and subjected to any further necessary treatment, while the glycerine, discharged into the sump 26, may be pumped back for re-use.

It is to be pointed out that thelnventionis applicable to the coating of a wide variety of filaments with a wide variety of material. For example, the filament may be a single or multiple strand of metallic wire, a single multiple thread of any suitable textile material, a single or multiple thread of natural or synthetic r'iibber, resins, plastics or fiberglass, onin fact, any filamentary substance which can be used with a minimum of tension.

If, for example, the invention is used to coat a solid or stranded copper wire, the coating material may be emulsions or dispersions oi 'plastl cized vinyl-acetate-vinyl chloride copolymers, plasticized polystyrene, polyethylene or other mixtures. The liquid carrier in such cases will be material used to destabilize the emulsion,- or to change the liquid coating into asolidcoat ing by any suitable chemicalor physical change required. a

The invention is equally applicable to the'coaffi ing of threads or cords with natural or synthetic rubber, natural or synthetic resin, cellulosederivatives, waxes, or any other mixtures. Likewise, the original filament may be a copper wire which may then be coated with suitable aspha'iti'c materials, waxes, paints or lacquers.

Another use for "the present invention, involving the principles outlined above, is in the iormation of small hollow filaments. merely involves the coating of a central filament with, however, a materialfwhichfiocs notadhere "to this filament. After the coatingihas be'en applied in any one of the mannersabove,.:ithe

core may then be removed; leaving a hollow filamentary structure.

Accordingly, while I have, for "the but only as set forth im-th'e obiect's and -"the s claims which follow.

1' 4 .I claim: '1. "Apparatus for coating filaments comprising, a tube having a coating hardening and shaping portion of small uniform cross section throughtional shape desired for the coated filament,

means for continuously advancing a filament through said tube, means for flowing a coating liquid around said moving filament within said tube, and means for fiOWillg another liquid through saidtube and around said filament and its surrounding coating liquid, and means for controlling the new rates of said coating liquid and said other liquid in relation to the cross sectional-size of the tube to cause them to flow through the tube with viscous flow.

'2. Apparatus for coating filaments comprising, a met tube having a portion of small uniform cross section throughout its length to its exit end and of approximately the cross sectional shape desired for the filament coating, a second tube axially'aligned with said portion or" said first tube "and jpositioned to discharge into said portion of thegfirst tube, means for advancing said filament througli'said second tube into and through said portion of said first tube along the longitudinal 7 center line of said portion of said first tube, a

first reservoir and a first conduit communicating with-said second tube, a second reservoir and 'a--scond conduit means communicating between said second reservoir and said first tube and entering said first-tube in advance of said portion off the Ifirst'tube and in advance of the discharge end oisaidsecond'tube', and means for controlling-the flow of liquids from said reservoirs to control the :pres'sure of said liquids at their conjunction in said first tube and to regulate the pressure diflerentlal of said liquids.

Name Date 2;;I'99,'82 Inok'uchi ct al. "a.-- May "I, 1940 2,288,982 Waterman et al. July '7', 1942 "23561550 Ryan Dec. 21, i948 

